Coupled Microenvironments for Artificial Photosynthesis of a C ₆ Oxygenated Product from CO ₂

Research on solar fuels generation has aspired to mimic photosynthesis. Powered by sunlight, photosynthesis converts CO 2 and water into C 3 intermediates en route to C 6 oxygenates (sugars). This study reports an analogous artificial photosynthesis process, inspired by the biological principle of an assembly of coupled microenvironments to achieve multistep, selective chemical conversions to a desired C 6 product. Through four codesigned microenvironments working in concert, powered by simulated sunlight, this work demonstrates the conversion of CO 2 and water to 2-methyl-2-pentenal, a C 6 oxygenate. Specifically, a photovoltaic-driven electrolyzer with a Ag–Cu cathode converts CO 2 and water to H 2, CO, and C 2 H 4 . The products are fed into a photothermocatalytic reactor containing a dual-catalyst bed of Rh-PPh 3 /SBA-15 and TiO 2, which promotes ethylene hydroformylation to propanal, and subsequent propanal aldol condensation to 2-methyl-2-pentenal, a product convertible to hexane, a liquid fuel. This study presents an outline for codesigning assemblies of microenvironments that enable the conversion of CO 2 to C 6 products.